Automatic slack adjuster



Feb; 16, 1932.

H. E. ANDERSON AUTOMATIC SLACK ADJUSTER Original Filed Sept. 12, 1930 2 Sheets-Sheet 1 ATTORNEY 2' Sheets-Sheet 2 INVENTOR WMM ATTORNEY H. E. ANDERSON AUTOMATIC SLACK ADJUSTER Feb. 16, 1932.

Original Filed Sept. 12, 1930 Patented Feb. 16, 1932 warren STATES PATENT OFFICE HARLEY E. ANDERSON, OF KANSAS CITY, MISSOURI, ASSIGNOR TO GUSTIN-BACON MANUFACTURING 00., OF KANSAS CITY, 1VIISSOURI, A CORPORATION OF MISSOURI AUTOMATIC SLACK ADJUSTER Original application filed September 12, 1930, Serial Nci. 481,418. Divided and this application filed ember 16, 1930. Serial No. 489,075.

My invention relates to that class of automatic slack adjusters, such as is described in my copending application, Serial No. 481,418,

ot which this is a division.

My invention hasi'or its object, to provide an improved structure to be mounted on the top'rod intermediate the live truck lever and the cylinder lever, the device being constructed so that it will automatically maintain the piston travel in the air brake cylinder with out regard to the wear on the brake shoes, thus producing a device which will insure uniform application of the brakes throughout the entire length of the train. My invention has for its further object, to provide for the convenient manipulation of the device when the brake shoes are worn out and new shoes are being applied.

A concrete embodiment of my invention is illustrated in the accompanying drawings, to be considered as a part of this specification, in which Fig. 1 is a phantom top plan view through the floor of a freight car equipped with my improved automatic slack adjuster; V

Fig. 2 is an enlarged fragmentary detail view of the device as shown in Fig. 1;

Fig. 3 is an enlarged detail view of the device in side elevation and Fig. 4 is a similar view showing the slack adjuster mechanism in section.

Similar reference numerals refer to similar parts throughout the entire description.

In Fig. 1 of the drawings, which is more or less diagrammatic, I show my improved automatic slack adjuster applied to a car which is equipped with a standard air brake cylinder 1 and piston rod 2. This rod 2 is connected to a cylinder lever 3, to the end of which is pivotally secured, by means of a pin or pivot 4:, a two-piece top rod5 and5'. By means of a link 6, the cylinder lever 3 is connected to a cylinder dead lever 7, the end of which is secured to another two-piece top rod 8 and 8. These top rods 5, 5, and 8, 8', are connected to the live truck levers 9 and 10. In the hereinafter-contained description I shall confine myself to the device as applied to the top rod 5, 5, for the reason that the construction of the device and its mounting upon the other top rod 8, 8', is identical. r

The top rod is provided with a threaded portion 11, which screws into internal threads 12 formed in an upwardly-extending portion on a housing 13, and nut 14: being provided to lock the top rod 5 securely in place. The housing 13 is provided with a downwardlydepending portion in which I form a cylinder 15, into which extends a telescoping sleeve-16 formed on a supplemental housing 17. supplemental housing 17 is provided with an upwardly-extending portion 18, which is fitted to and slidable upon the top rod '5. A coil spring 19 is mounted within the telescoping sleeve 16 and the cylinder 15, and serves to hold the housing 13 and the supplemental housing 17 normally apart. housing 13 and the supplemental housing 17 are provided with wells 20 and 21, in which are mountedspring-pressed dogs 22 and 23,

these dogs 22' and 23 being held normally projected from said wells 20 and 21 by means of coil springs 24 and 25.

The other part 5 of the top rod is secured to the live truck lever 9 by means of asuitable pin or pivot 26. This part 5 of the top rod is provided with a threaded portion 27, which is fitted to internal threads 28 cut adjacent the forward end of a cylindrical rack 29. This rack 29 slides through the downwardly-depending portion of both the iousing 13 and the supplemental housing 16, intermediate the top rod 5 and the sleeve 15 and telescoping sleeve 16. This forward these teeth 32 being adapted to engage the dogs 22 and 23, to preventrearward move-- ment.

I mount a permanent stop bracket 33 on the bottom of the car, in position so that it will engage the wall of the well21 of the I The The

,1 r r end or the rack-2:) 1s provlded with a periphsupplemental housing 17 at a predetermined time. This permanent stop bracket 33 should be so located as just to touch the device at the desired piston travel.

The operation of the device is as follows: Air being admitted into the cylinder 1, its piston shifts the cylinder lever 3. This moves the top rods 5, 5, 8, 8, and consequently the live truck lovers 9 and 10, and the brakes are applied. By setting the device so that with a piston travel of not less than seven nor more than nine inches-which is the required limitation of air brake piston travel-the supplemental housing 17 will abut the permanent stop bracket 33. As the brake shoes wear, the top rods 5, 5, 8, 8, will tend to move the supplemental housing 17 farther. Inasmuch as this cannot be done, by reason of the permanent stop bracket 33. the result will be that the coil spring 19 will be compressed, and the supplemental housing 17 will move until the telescoping sleeve 16 has entered the cylinder 15. This rearward movement of the supplemental housing 17 will result in depressing the dog 23 until it is in a position to engage the next succeeding tooth or teeth 32 on the cylindrical rack 29, until the movement is suilicient to take up any slack produced in the brake rigging by the wear of the brake shoes. Upon the release of the brakes, the spring 19 will immediately expand to its normal size. and this will result in moving the housing 13 rearwardly along the rack 29, and this in turn will cause the dog to slide over the teeth 32 of the cylindrical rack 29 until the dog 22 engages the correct tooth 32 on the rack 29 to correspond with the number of teeth 32 which the dog 23 has been advanced.

Inasmuch as this operation takes place whenever there is sutlicient slack in the brake rigging to permit the adjuster to take up a tooth 32, it follows that I am able to maintain at all times the same amount of piston travel in the air brake cylinder and the consequent efficient operation of the brakes.

In applying new shoes, where the brake shoes are worn out, the workman may disconnect either the top rod 5 from the cylinder lever 3, or the top rod 5 from the live truck lever 9. By turning the top rod 5, 5, a quarter turn, the teeth 32 of the rack 29 will be moved out of engagement with the dogs 22 and 23, and the rack 29 can be pulled back to restore the top rod 5, 5, to its original length, the peripheral flange 30 serving to prevent the rack 29 being entirely drawn out of the supplemental housing 17.

Having described my invention, what I regard as new, and desire to secure by Let ters Patent of the United States, is:

1. An automatic slack adjuster, comprising the combination, with a brake rigging having cylinder levers, brake shoes, live truck levers, lower rods and two-piece top rods which connect said cylindrical levers to said live truck levers, of a cylindrical rack fixedly mounted on one part of each top rod, 21 housing carried by the other part of each top rod, which encloses said cylindrical rack, a sleeve in said housing, a supplemental housing slidably secured to said other part of said top rod, a telescoping sleeve thereon, slidable in the first named sleeve, means tending to thrust the sleeves apart, pring-actuated dogs in said housings, and stops for said supplemental housings.

2. An automatic slack adjuster, comprising the combination, with a brake rigging having cylinder levers, brake shoes, live truck levers, lower rods and two-piece top rods which connect said cylinder levers to said live truck levers, of a cylindrical rack fixedlymounted on one part of each top rod, a housing carried by the other part of each top rod, which encloses said cylindrical rack, a. sleeve in said housing, a supplemental housing slidably secured to said other part of said top rod, a telescoping sleeve thereon, slidable in the first named sleeve, springs which tend to thrust said sleeves apart, spring-actuated dogs in said housings, and stops for said supplemental housings.

3. An automatic slack adjuster, comprising the combination, with a brake rigging,- of a two-piece top rod, a housing fixedly secured to one part of said top rod, a cylindrical rack fixedly secured to the other part of said top rod, said rack having ratchet teeth on its lower side, said rack being slidable in said housing, means on said rack which prevents its rearward withdrawal from said housing, a supplemental housing which telescopes the first named housing, a spring which holds said housings normally apart, spring-actuated dogs in said housings which engage the teeth on said rack, and a permanent stop which said supplemental housing abuts.

4. In an automatic slack adjuster, a twopiece top rod, a cylindrical rack fixedly secured to one part of said top rod, teeth out on the outside of said rack, a housing fixedly secured to the other part of the top rod, in which said rack slides, a supplemental housing, a spring which holds said housings normally in spaced position, a dog mounted in each housing, springs to hold said dogs normally in engagement with the teeth on said rack, and a permanent stop against which said supplemental housing abuts.

5. An automatic slack adjuster for a brake rigging, comprising a two-piece top rod which constitutes a connection between the cylinder lever and the live truck lever, a cylindrical rack, having ratchet teeth thereon, fixedly secured to a part of said rod, the other part of said rod carrying a housing in which said rack slides, a sleeve in said housing, a supplemental housing slidably secured to said other part of said rod, a telescoping sleeve thereon, slidable in the first mentioned sleeve, dogs in said housings which normally engage said ratchet teeth, and a permanent stop against which said supplemental housing abuts.

6. An automatic slack adjuster for a brake rigging, comprising a two-piece top rod which constitutes a connection between the cylinder lever and the live truck lever, a cylindrical rack, having ratchet teeth thereon, fixedly secured to a part of said rod, the other part of said rod carrying a housing in which said rack slides, a sleeve in said housing, a supplemental housing slidably secured to said other part of said rod, a telescoping sleeve thereon, slidable in the first mentioned sleeve, dogs in said housings which normally engage said ratchet teeth, resilient means which hold said dogs in said engagement, and a permanent sto against which said supplemental housing a uts.

HARLEY E. ANDERSON. 

